How Ambiguity Became a Tool for Managing the U.S.-Kurdish Alliance

The United States has treated ambiguity about its own commitment as a tool for managing the Kurdish alliance. From Barzani’s rebellion in the 1970s to the Peshmerga partnership and the Syrian Democratic Forces, that vagueness allowed disproportionate cooperation to be extracted while keeping the freedom to withdraw whenever the costs outweighed the value.

For more than fifty years, the Kurds have occupied an unusual place in American foreign policy. They have supplied ground troops, intelligence, and territorial control at a fraction of the cost the United States would otherwise have paid. They have done so while receiving no treaty, no formal security guarantee, and only a shifting set of informal assurances about how long support would last. The pattern reappears across three episodes separated by decades and different Kurdish populations. It appears in the CIA’s covert backing of Mulla Mustafa Barzani’s rebellion in Iraq from 1972 to 1975. It appears again in the long partnership with the Iraqi Peshmerga against the Islamic State. And it appears a third time in the rise and eventual dissolution of the Syrian Democratic Forces between 2014 and 2026. In each case, American support was substantial enough to sustain the Kurdish military effort, but also vague enough that the country supplying it kept full freedom to change course later. Glenn Snyder’s alliance security dilemma helps explain why a patron would choose this path on purpose. Ambiguity about a patron’s own reliability functions as a bargaining tool. It keeps a dependent partner working hard to earn continued favor, since nothing has been promised outright.

The Logic of Ambiguity in Asymmetric Alliances

Snyder frames the core tension of any alliance as a trade-off between two fears. A state can be abandoned by an ally who fails to honor an implicit or explicit commitment. Alternatively, it can be entrapped in a conflict over an ally’s interests that it shares only partially. These risks move in opposite directions. A strong, explicit commitment lowers the fear of abandonment, but it raises the danger that the encouraged partner will drag the stronger state into a war it did not choose. A weak or vague commitment restrains the partner and limits entrapment, but it leaves the weaker side unsure whether help will come when needed.

Snyder is explicit that keeping a commitment vague reflects strategy more than diplomatic accident. States in a multipolar setting usually want to keep their commitments tentative for as long as possible, to preserve the option of shifting to a different partner and to maximize leverage over the current one by showing that alternatives exist. Ambiguity does double duty here. First, it reassures the stronger partner that it can walk away if costs rise. Second, it disciplines the weaker partner into moderation, since an ally who cannot count on rescue tends to avoid provoking a crisis that would require one. Snyder makes the point plainly, noting that bargaining power over the ally is enhanced by a weak commitment while leverage over the adversary requires a firm one. A patron wants both at once, so it usually settles for whichever mixture serves the moment best.

Dependence sharpens the effect of this ambiguity. A state’s need for outside help, weighed against its partner’s capacity to supply it, determines how strongly it will fear abandonment. That fear grows under vagueness, and is calmed, though never removed, by an explicit contract. A materially dependent ally has no alternative patron to turn to. It keeps proving its usefulness, hoping that usefulness will eventually be rewarded with something firmer. Security scholar Iain Henry argues that when a state is confident its ally’s interests align with its own, and the alliance poses no risk of either abandonment or entrapment, that ally counts as reliable, and reliability, not innate loyalty, is what states actually want from allies. The Kurds, across six American administrations spanning half a century, have lived inside this arrangement. They supplied the military value a patron with limited willingness for direct regional involvement wanted. In return, the patron withheld the one thing that would have made the partnership durable, something it could be held to in the open.

Iraq, 1972 to 1975, and the Barzani Precedent

The first and starkest episode began in 1972, when the Shah of Iran asked the United States to join Iran and Israel in covertly arming Barzani’s long-running rebellion against the Iraqi government, then drawing closer to the Soviet Union after signing a friendship treaty with Moscow. Nixon approved the program within a few months. Henry Kissinger managed it personally, kept it hidden from the State Department, and renewed it annually at roughly five million dollars a year, framing it to Nixon as a modest cost for tying down Iraqi forces and denying the Soviet Union a freer hand in the region. The American contribution stayed small enough to preserve deniability, and it also remained large enough to keep the insurgency alive. The CIA later called the operation a uniquely useful tool for that purpose.

The House Select Committee on Intelligence, chaired by Otis Pike, later found that Iranian support for Barzani dwarfed the American contribution, and that American assistance functioned largely as insurance, a signal that the insurgency would not be dropped overnight by the Shah. That insurance proved worthless. When Iraq and Iran settled their border dispute over the Shatt al-Arab waterway in March 1975, the Shah closed the border to the Kurds within days. The Pike Committee found that the Shah’s leverage over American policy was such that he made no effort to notify his junior American partners that the program’s end was imminent. Barzani’s fighters, out of ammunition and options, were overrun within weeks, leaving thousands dead in the collapse.

This episode matters to the reliability argument because the American commitment was built from the outset to be revocable without cost. Aid flowed through Iran, so the decision to end it belonged to Tehran, and no promise was ever made publicly that could later be enforced or even cited. A Pike Committee witness, described only as a high American official, told committee staff that covert action should not be confused with missionary work, a line later attributed by some to Kissinger himself, though the report does not name him. The Kurds fought a three-year war believing American backing stood behind them, and in a narrow sense it did. However, the backing had been arranged so that withdrawing it would cost the United States nothing. The mechanism here differs from the later cases. Iran served as the intermediary, so this was ambiguity achieved by hiding behind someone else’s discretion, a more sophisticated form of deniability than declining to put a promise in writing.

Iraq After 2014, Partnership Without a Promise

The pattern reappears, in a gentler form, in the long relationship with the Iraqi Peshmerga after the Islamic State’s advance in 2014. The Department of Defense first signed a memorandum of understanding with the Kurdistan Regional Government in 2016, when the Islamic State still held large parts of Iraqi territory, and it has renewed and updated that memorandum since, most recently for a further four years in 2022. The relationship is genuine and long-running, and American officials describe it in the language of partnership and shared sacrifice. It remains, all the same, a memorandum that can be renewed or revised, not a binding treaty. Its scope has already narrowed as the threat it was built to answer has receded. In a 2026 statement framed mainly as a denial that support had been cut off, the Peshmerga Ministry acknowledged in passing that assistance tied specifically to counter-Islamic State operations had been paused, while insisting broader cooperation continued on a timeline running only through September of that year. The relationship survives, but its own terms remind both sides that survival was never guaranteed past the date written into the current agreement.

Syria, 2014 to 2026, From Kobane to Dissolution

The Syrian case compresses this cycle into little more than a decade. The United States built the Syrian Democratic Forces in 2015 out of the Kurdish fighters who had defeated the Islamic State at Kobane, judging them a reliable partner for the wider campaign against the group. By 2017, Syrian Kurds believed their cooperation had earned them what the academic and columnist Henri Barkey called a renaissance, a period when American backing seemed to promise durable autonomy in the northeast. The break came in October 2019, when President Trump ordered American forces to step aside from the Turkish border, telling reporters the Kurds had been paid massive amounts of money for their service, and that Turkey, Syria, Iran, Iraq, Russia, and the Kurds would have to figure the situation out among themselves. An SDF spokesman said there had been assurances that no Turkish operation would be allowed against the region, and called the pullout a stab in the back. The episode replicated, almost exactly, the Barzani sequence forty-four years earlier. It combined substantial reliance on Kurdish fighters, an informal sense of assurance among those fighters, and a withdrawal decided unilaterally and announced only once it was already underway.

The final period arrived after the fall of the Assad government in December 2024. The United States built a new relationship with Syria’s transitional leadership under Ahmed al-Sharaa, and according to Kurdish accounts, it promptly dropped the SDF in favor of the new authorities. Al-Sharaa and Abdi signed a framework agreement in March 2025 committing to integrate SDF institutions into the Syrian state by the end of that year, alongside a ceasefire and constitutional guarantees for Kurdish rights. That deadline slipped for roughly ten months before fighting broke out in January 2026, costing the SDF most of the territory it had held in the northeast, and that month the two sides signed a second agreement on a phased integration of its military and civilian institutions. Commander Mazloum Abdi spent the following months describing the agreement as conditional on an American guarantee that never fully arrived. In February, he told an interviewer that the SDF was waiting for President Trump to fulfill his promise, and that Kurdish negotiators had asked for a guarantee mechanism to ensure the deal was implemented and monitored, precisely because no binding one yet existed. In August 2026, Abdi announced the SDF’s full dissolution as an independent force, its roughly ten thousand remaining fighters folded into Syrian army brigades organized around Kurdish majority towns, closing fourteen years of self-rule in the northeast. The Trump administration’s Syria envoy called the transition historic and credited the president’s leadership for it, language that registered the outcome as an American diplomatic success, even as it marked, for the Kurds, the last stage of the autonomy they had built around American backing.

Signals of Preserved Ambiguity

A separate question is whether the United States has ever signalled, in plain terms, that it wants the Kurdish question kept open rather than settled, and whether it has acted to prevent Kurdish moves toward statehood before they went too far. The evidence answers both parts clearly. In January 1970, before the Barzani operation even began, a State Department memorandum stated flatly that the United States did not support the concept of an autonomous Kurdish entity and did not wish to become involved, even indirectly, in anything that would encourage separatist aspirations. A CIA cable from the same period recorded the same caution from the American ambassador on the ground.

By March 1974, with the covert program already underway, a CIA memorandum described both the Shah and the United States as sharing an interest in a stalemate, one in which Iraq stayed weakened by Kurdish refusal to give up its autonomy, but in which neither patron wished to see the underlying dispute resolved in either direction. That stands as a direct statement of policy, distinct from a later inference drawn from events. The United States and Iran wanted the Kurdish movement strong enough to keep pressure on Iraq’s government, and weak enough that it could never become a state whose sovereignty would need recognizing or defending.

The same posture reappeared decades later, in a very different Kurdish setting. When the Kurdistan Regional Government in Iraq scheduled an independence referendum for September 2017, the White House said in advance that it did not support the vote and urged Kurdish leaders to call it off in favor of dialogue. The State Department repeated that the referendum was a distraction from the campaign against the Islamic State and warned of costs to trade and stability. After the vote passed overwhelmingly, Secretary of State Rex Tillerson said the United States did not recognize the result and continued to support a united, federal Iraq. Iraqi forces then moved to retake Kirkuk and other disputed territory from Kurdish control within weeks, without American intervention to stop them.

Taken together, these episodes show a consistent preference. The United States has been willing to arm, train, and fund Kurdish forces on a large scale, but it has also worked, sometimes explicitly, to keep the underlying political question of Kurdish self-determination from ever being resolved in the Kurds’ favor. While military cooperation was encouraged, statehood remained off the table. That combination kept Kurdish forces useful and dependent at the same time, which is exactly what a patron managing an asymmetric alliance would want if its aim were to preserve leverage rather than to see the relationship reach a fixed and final settlement.

Ambiguity as a Form of Extraction

These episodes form a pattern too consistent to be coincidence, and while only the 1970s case comes with a written record of intent, the repetition across three decades makes that intent hard to write off as accident. In 1972, American aid to Barzani flowed through Iran, so the decision to end it belonged to someone else. In 2019, American assurances to the SDF stayed informal enough that officials could later dispute whether they had been made at all. In 2026, the guarantee mechanism the SDF sought before agreeing to dissolve never took the form of a signed instrument, leaving Abdi publicly waiting on a promise rather than holding a written commitment. Each time, the ambiguity did what Snyder’s framework predicts. It kept the Kurdish side working hard to earn continued favor, since nothing was owed to them by right. It kept the American side free to recalculate whenever the cost of the relationship began to outweigh its value, whether that cost was confrontation with Iran in 1975, with Turkey in 2019, or with Syria’s government in 2026.

This is why calling Kurdish overextension naive gets the incentives backwards. A Kurdish leadership facing existential threats from Iraq, Turkey, or the Islamic State, and possessing no alternative patron capable of matching American military support, had every reason to accept ambiguous assurances over the absence of any assurance at all. It had every reason to fight as hard as it could to make itself indispensable, in the hope that indispensability would eventually harden into a firmer commitment. It never did, because a patron that let ambiguity harden into commitment would give up the very leverage that made the relationship cheap to run. Snyder observed that a formal, explicit contract reduces a dependent ally’s fear of abandonment, but correspondingly narrows the stronger partner’s freedom to escape entrapment on the issues that contract covers. The United States has avoided that narrowing at every turn, favoring instead a series of memoranda, informal assurances, and unwritten understandings, each revisable on its own timeline. The cost of that arrangement has fallen, across five decades and two countries, on Kurdish fighters who could never be certain, until the moment arrived, whether the ground beneath them would hold.

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